<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .earthrotate{
        width: 310px;
        height: 310px;
        background-image: url(images/earth.png);
        border-radius: 200px;
        /*设置坐标系*/
        position: relative;
        /*创建动画，设置参数
        它的速度不均匀,前快,后慢不统一.解决方法:参数linear
        */
        animation: run 60s linear infinite;
        
    }
    .earthrotate:hover{
        /*鼠标移入，地球暂停旋转。鼠标移除，继续旋转*/
        animation-play-state: paused;
        }
    
    
   /*定义动画关键帧
     变形(形状的变化)tranform
    */
    @keyframes run{
        from{transform: rotate(0deg);}
        to{transform: rotate(360deg);}
    }
</style>
<body>
    <div class="earthrotate"></div>
</body>
</html>